Scarring after surgery
How your scar heals after surgery depends on many factors but the most important one is genetic. Some people have very thin, faint scarring and some have darker, wider scars. Of course technique matters also. However, scars in the breast crease (bottom of the breast) are well hidden. So, if you have a bad scar, it is not visible in bathing suits or other clothing. I would recommend having a consultation with an experienced, board certified plastic surgeon to discuss your options in person. You may be a candidate for a scar revision at the time of your surgery.
Poor scars are a genetic/healing issue, not location of incision issue!
If you have poor scars on the basis of (your personal) genetics of healing, then using a different incision location will only give you another set of bad scars!
If you simply had a closure that healed poorly due to inflammation, bacterial contamination, or bleeding, for example, using the old scars and revising them will have a reasonable chance of improving them.
Why would you want dark poor scars in 4 locations? Even if the new scars heal poorly again, then at least you only have two bad scars rather than 4. Best wishes! Dr. Tholen
Incisions for revision
You can possibly have a periareola incision for a revision as well. It depends upon the type of surgery, size of implants, and size of your areola.
I recommend you use the same scar and not put any additional scars on the breast. Your skin may heal that way and I would hate for you to have more scarring elsewhere. After 4 years, it is technically OK to go through the same incision. Best of luck.